<template>
  <Demo v-if="ish"></Demo>
  <button @click="ish = !ish">显示/隐藏</button>
</template>

<script>
import { onBeforeMount, ref } from 'vue';
import Demo from "./components/Demo.vue";
export default {
  name: "App",
  components: { Demo },
  setup(){
    let ish=ref(true)

   

    return{
      ish
    }
  }
};
</script>

<style>
</style>
